1. Field of the Invention
The present invention relates to a sheet feeding apparatus for separating and feeding out stacked recording media (sheets) one by one to a recording portion or other portions.
2. Description of the Related Art
Nowadays, pursuant to the remarkable progress of information processing equipment, various recording systems such as printers, electronic typewriters and the like have been used in various offices. In such recording systems, plain paper sheets and/or thicker sheets such as post cards, envelopes and the like are used as recording media, and the recording media can be manually inserted and/or can be automatically supplied to a recording portion by an automatic sheet feeding apparatus. To this end, the recording system is provided with a manual sheet insertion opening and a sheet supply opening for the automatic sheet feeding apparatus to cope with various recording media. Further, since the above-mentioned automatic sheet feeding apparatus are generally of a separating claw type which can be made inexpensive, the kind of recording media which can be stably separated is limited to the plain paper sheet alone. Thus, in order to supply or feed the thicker sheets such as post cards, envelopes and the like, an exclusive automatic sheet feeding apparatus of other separation type, for example, of a friction separation type must be used.
However, in the conventional cases, when the plain paper sheets and the thicker sheets such as post cards are to be used each in its proper way as the recording media, the corresponding automatic sheet feeding apparatuses must be exchanged with respect to the recording system each time, thus worsening the operability and requiring an additional installation space for the dismounted automatic sheet feeding apparatus.
Further, even when the automatic sheet feeding apparatus for the plain paper sheets is incorporated into the recording system and only the automatic sheet feeding apparatus for the thicker sheets is detachably mountable within the recording system, since the recording system itself becomes large-sized, the installation space for the recording system will be increased. Furthermore, since at least two automatic sheet feeding apparatuses are required the overall recording facilities will be expensive. In addition, since not only the sheet supply opening for the automatic sheet feeding apparatus but also the manual sheet insertion opening are required, the overall recording system becomes large-sized and expensive.